Braking apparatus



Feb. 2l, 1933.

B. DICK 1,898,036

BRAKING APPARATUS Filed May 1s, 1932 Atty.

BURNS DICK, OF FEBGUSQN, MISSO Vindicates the drum Patented Feb. 2l, 1933 `UNITED -s'rlrrss URI, ASSIGNOR TO WAGNER ELECTRIC 0F ST. LOUIS, MISSOURI, A CORPORATION OF DELAWARE PATENT oFFlcE coaronarzon,

BEARING APPARATUS Application filed .lay 18,

I braking My invention relatesto vehicle o an 1mapparatus and more particularly t provement in band brakes of the t in which the reinforcing web has been divided intermediate the ends of the band into two spaced apart portions to decrease the initial pressure necessary.. to engage the band with the drum.

Gne of the objects of m invention is to provide a band brake of t e type referred to with a radial ressure ap lying device acting on the band3 adjacent tiie end of the rear web portion and receiving its actuating forcesfrom the torque of the forward portion of the band.

Another object of my invention is to rovide connecting means between the forward web portion of the band and the radial pressure applying device for the rear web portion that will produce an effective anchor point for the band at a point spaced ahead of the actual stop or anchor provided by the radial pressure applyingli device.

Still another object of my invention is to produce an improved radial pressure applyA ing device for a band brake which will apply its pressure at a point closely adjacent the lining carrying portion.

Other objects will become apparent from the following description. of one embodiment of my invention taken in connection with the accompanying drawing in which Figure 1 is a side elevation of a brake assembly (the drum being shown in cross section) embodying my improved brake band; Figure 2 is a cross sectional view on the line 2--2 of Figure 1; and ,Figure 3 is a cross sectional view on the line 3 3 of Figure 1. Referring to the drawing, the numeral 1 of the brake which is secured in the usual manner to the wheel of the vehicle and is` enclosed on its open side by a backing plate or support 2 secured to some xed part of the vehicle. The brake shoe 3 is of the band type and is mounted within the drum and adapted to have its ends expanded into engagement with the drum by suitable means such as the hydraulic mechanism 4. The band is 112 and 13 ar 1932. Serial No. 811,587.

biased to off position by the usualsprin 5, its olf position clearance at each en being determined by the adjustable stops 6. The brake band 3 is of the T-section type and comprises a lining receiving flange 7 and a reinforcin web 8. The web 8 vcomrises two spaced apart portions 9 and 10 ormed by .cutting out a piece of the web at the center of the band. The lining 11 of the band is omitted over the portion of the iange lthat is not reinforced by the web, i thus permitting a saving in lining as such portion of the flange, if covered by lining,l would perform very little braking action in this type of brake. A pair of link members l2 and 13 are pivoted at 14 to the end of the web portion 9 and extend across the cut-away portion of` the webto a point beyond the endof the Aweb portion l0 where their free ends bear on the flange 7 The free ends of the links e provided with inclined sur-4 ectively, which cofaces 15 and 16, resp operate through a roller 1'?" with a pair of inclined surfaces 18 and 19 on a vpair of abutments 20 and 21 ositioned on opposite sides of the web portion 10 and secured to the backing plate.y The abutments 20 and 21 are held in spaced relation by a suitable spacer 22. It is to be noted that the roller 17 extends through an over-size opening 23 in the web portion 10, the purpose of w ich is to cause the radial pressure produced by thel inclined surfaces and the roller (as hereinafter described) to be applied on the band at a point as close as possible to the inner surface of the llange 7.

An anchor pin 24 having bearing in the backing plate is provided with an eccentric portion 25 which extends through slots 26 and 27 in the link members 'l2 and 13, the slots being adjacent the end of the web portion 10 topermit the end to engage the'pin 24 to anchor the band when the drum is rotating in a direction opposite to the arrow (Fi re 1). A flange 28 and a washer 29 on t e pin prevent the links 12 and 13 from spreading apart. The eccentric portion of the anchor pin may be adjustedby unscrewing the nsI securing nut 30 and turning the pfin. u

'web portion 10. Assuminfr In order to adjust the off position of the central portion of the band to compensate for wear on the lining, an eccentric cam stop 31 1s provided on the backing plate to cooperate with the top edges of the links.

Referring to the operation of the brake, when the hydraulic mechanism is actuated to expand the band, the initial pressure required to en age the band with the drum is that require to overcome the spring 5 and to bend the flange 7 at its central portion since the ends of the web portions 9 and 10 are not restrained from relative movement, the links 12 and 13 not being secured to the that the drum in a forward direction (that is to say, its direction during forward motion of the vehicle), as indicated by the arrow in Figure 1, the band, when engaged, will have a slight circumferential movement with the drum, which movement will cause the links 12 and 13 to transmit the torque of the forward part of the band to the roller 23 and thereby produce a radial pressure on the band adjacent the end of the web portion 10. The amount of radial pressure on the band can be varied as desired by changing the angle of the inclined surfaces.

It is to be noted that while the inclined the roller form the actual anchor for the band in the forward direction of rotation of the drum, the effective anchor is at the pivot 14 spaced ahead of the radial pressure device since the links 12 and 13 are not integral with the ange. rIhe effective anchor at pivot 14 causes the band, when engaged with the drum, to rotate around the pivot, the portion ahead of the pivot being forced toward the drum and the portion at the rear ofthe pivot being forced away from the drum` Since the band near the rear kof pivot 14 is not provide with brake lining, the fact that it is forced away from the drum has no effect upon the braking action. The forcing away of the unlined portion of the band has no effect upon the band adjacent the end of the web portion 10 as such receives a radial pressure by means of the links l2 and 13 and the radial pressure applying device.

By placing the axis of the roller 17 closely adjacent the lining carrying portion of vthe band, the distance between the point of contact of the band with the roller and the point of application of circumferential force (the lining surface) is decreased, thus decreasing the tendency of the band to rotate around the roller, which reactive effect has the undesirable result of producing a distortion of the band which increases the braking pressure immediately forward of the roller and decreases it at. the rear of the roller.

when the drum is rotating in a reverse directlon, the band is anchored by the adjustis rotating surfaces and apart ends intermediate the ends of t able pivot pin 24 and no radial pressure is produced on the band by the inclined surfaces and the roller. By proper adjustment of the anchor pin when the band is in off position, the end of the web portion 10 can be maintained in contact with the pin 24 and the inclined surfaces in Contact with the roller, thus eliminating any clicking of the parts as the band is actuated to engage it with the drum in eitner direction of rotation.

Having fully described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. In braking apparatus the combination of a drum, a brake band adapted to have its ends expanded into engagement with the drum, said band comprising a lining carrying portion and a reinforcing web and said web comprising two portions havin s aced apart ends intermediate the ends of tgiie band, means connected to the end of one of said web portions and extending to a point adjacent the end ofthe other web portion, and means for applying an outward pressure to the band, said pressure being transmitted through said rst named means.

2. In braking apparatus the combination of a drum, a brake band adapted to have its ends expanded into yengagement with the drum, said band comprising a lining carrying portion and a reinforcing web and said web comprising two portions havino spaced Y e band, a member pivotally connected to the end of one of said web portions and extending to a point adjacent the end' of the other web portion, and means for applying an outward radial pressure on the band at a point adjacent to one end of said member.

3. In braking apparatus, the combination of a drinn, a brake band adapted to have its ends expanded into engagement with the drum, said band comprising a lining carrying portion and a reinforcing web and said web comprising two portions havin s aced apart ends intermediate the ends of t e and, a link pivotally connected to the end of one of said web portions and cooperating with the band adjacent the end of the other web portion, and means for 'applying a radial pressure on the link.

4. In braking a j paratus, of a drum, a bra e band adapted to have its ends expanded into engagement with the drum, said band having a slight circumferential movement with the drum, said band comprising a lining carrying portion and a reinforcing web and said web comprising two portions having spaced apart ends intermediate the ends of the band, a member connected to the end of one of said web portions and in engagement with the band at a pointadjacent the end of the and means for transferother web portion,

the combination i ICO ring the slight circumferential movement of the member with the band into a radial pressure on thev band.

5. In braking apparatus, the combination of a drum, a brake band adapted to have its ends expanded into engagement with the drum, said band having a slight circumferential movement with the drum, said band comprising a lining carrying portion and a reinforcing web and said web comprising two portions having spaced apart ends intermediate the ends of the band, a member pivoted to the end of one of said web portions and in sliding engagement with the lining carrying portion of the band at a point adjacent the end of the other web portion, and means for applying a radial pressure to said member adjacent its point of engagement with the lining carrying portion of the band.

6. In braking apparatus, the combination of a rotating drum, a brake band adapted to have its ends expanded into engagement with the drum, said web comprising a lining carrying portion and a reinforcing web and said web comprising two portions havingspaced apart ends intermediate the ends of the band, a member connected to the end of one of said web portions and engaging the band at a point adjacent the end of the other web portion, means for anchoring said band and applying a radial pressure on said link at a point adjacent the end of said last named web portion when the drum is rotating in one direction, and means for anchoring the band when the drum is rotating in the other direction.

7. In braking apparatus, the combination of a drum, a brake band 'adapted to have its ends expanded into engagement with the drum, said band having a slight circumferential movement with the drum, said band comprising a lining carrying portion and a reinforcing web and said web comprising two portions having spaced apart ends intermediate the ends of the band, a member connected to the end of one of said web portions and in engagement with the band at a point adjacent the end of the other web por-- tion, said member being provided with an inclined surface adjacent its point of engagement with theband, a fixed abutment member having an inclined surface, and a roller in rolling Contact with said inclined surfaces.

8. In braking apparatus, the combination of a drum, a brake band adapted to have its ends expanded into engagement with the drum, said band having a slight circumferential movement with the drum; said bandcomprising a lining carrying portion and a reinforcing web and said web comprising two portions having spaced apart ends intermediate the ends of the band, a pair of members pivoted to the end of one of said web portions and in engagement with the lining carrying-portion of the band at a `point adjacent each side of the end of the other web portion, each of said members being provided with an inclined surface adjacent its point of engagement with the band, a fixed abutment member on each side of the last named web portion and provided with an inclined surface, and a roller in rolling contact with said inclined surfaces.

9. In braking apparatus, the combination of a drum, a brake band adapted to have its ends expanded into engagement with the drum, said band having a slight circumferential movement with the drum, said band comprising a lining carrying portion and a reinforcing web and said web comprising two portions having spaced apart ends inp termediate the ends of the band, a member connected to the end of one of said web portions and in engagement with the band at a point adjacent the end of the other web portion, means for anchoring said band and applying a radial pressure on said member at a point adjacent the engagement of the member with the band when the drum is rotating in one direction, said means comprising an inclined surface on the member, a stationary inclined surface and a fioating roller in rolling contact with said surfaces, and adjustable means for anchoring the.

band when the drum is rotating in the other direction, said adjustable anchor maintaining the roller in contact with the inclined 'surfaces when the band is in off position.

10. In braking apparatus, 4the combination of a support, a rotatable drum, a friction member adapted to cooperate with the drum and comprising a lining carrying portion and areinforcing web, said member being capable of slight circumferential movement with the drum, means for applying radial pressure to said member, said means comprising an inclined surface carried by the friction member, an inclined surface carried by the support, and a roller interposed between and in rolling contact with the inclined surfaces, said roller lying between the inner edge of the reinforcing web and the lining carrying portion.

11. In braking apparatus, the combination of a support, a rotatable drum, a friction member adapted to cooperate with the drum and comprising a lining carrying portion and a reinforcing web, said member being capable of slight circumferential movement with the drum, means for applying radial pressure to said member, said means comprising an inclined surface carried bythe friction member, an inclined surface carried by the support, and a roller interposed between and in rolling contact with the inclined surfaces, the axis of said roller in the off position of the band lying closely adjacent the lining carrying portion of the band.

' l2. In braking apparatus, the combination of a support, a rotatable drum, a friction 5 member adapted to cooperate with the drum and comprising a lining carryin portion and a reinforcing web, said mem r being capable of slight circumferential movement with the drum, means for applying radial 1 pressure to said member, said means comrising an inclined surface carried by the riction member, an inclined surface carried by .the support, and a roller interposed between and in rolling contact with the in- 15 clined surfaces, said roller proecting through the web and lying closely a jacent the lining carrying portion of the band.

13. In braking apparatus, the combination of a support, a rotatable drum, a riction 20 member adapted to cooperate with the drum and comprising a lining carrying portion and a reinforcing web, said member beingcapable of slight circumferential movement with the drum, rneans for applying radial o pressure to said member, said means comprising a pair of inclined surfaces carried by the friction member and lyin on opposite sides of the web, a pair o m incline surfaces carried by the support W and lying on opposite sides oi the web in spaced relation to the first named inclined. surfaces, and a roller interposed between and in rolling contact with said pairs of in- ,5 clined surfaces, said roller extending through the web and provided with enlarged ends on each side of the web. In testimony whereof, I hereunto aix my signature, this 12th day of May, 1932. o BURNS DICK. 

